JPWO2019244842A1 - Resistor material for resistor, manufacturing method thereof, and resistor - Google Patents

Abstract

An object of the present invention is to provide a copper alloy sheet having both a small temperature coefficient of resistance and good press formability, a method for producing the same, and a resistance material for resistors. The object of the present invention is 5.0 to 20.0% by mass of Mn, 0 to 5.0% by mass of Ni, 0 to 5.0% by mass of Sn, and 0.1 to 10% of Ni and Sn in total. 0.0% by mass, the balance being Cu and unavoidable impurities, and the difference in elongation between the rolling parallel direction and the rolling width direction, which is perpendicular to the rolling direction, being 10% or less. Achieved by

Description

The present invention relates to a copper alloy sheet material, a method for manufacturing the same, and a resistor material for resistors.

The metal material of the resistance material used for the resistor may have a small temperature coefficient of resistance (hereinafter also referred to as “TCR”) so that the resistance of the resistor is stable even when the environmental temperature changes. Required. The temperature coefficient of resistance is the magnitude of change in resistance value with temperature expressed in parts per million per degree Celsius, and TCR(×10 ⁻⁶ /K)=(R−R ₀ )/R ₀ It is represented by the formula: ×1/(T−T ₀ )×10 ⁶ .

Here, T in the equation represents the test temperature (° C.), T ₀ represents the reference temperature (° C.), R represents the resistance value (Ω) at the test temperature T, and R ₀ represents the resistance value (Ω) at the test temperature T ₀ . .. Since the Cu-Mn-Ni alloy and the Cu-Mn-Sn alloy have a very small TCR, they are widely used as a metal material that constitutes a resistance material (for example, see Patent Document 1).

JP, 2016-69724, A

With the recent trend toward miniaturization and high integration of electric and electronic parts, miniaturization of resistance materials is also progressing. Along with this miniaturization, the cross-sectional shape when a metal material is press-molded to produce a resistance material has a great influence on the variation in the resistance value of the resistor. It is required to improve the press formability of the metal material of the resistance material having the fracture surface shape with reduced burr and egre.

An object of the present invention is to provide a copper alloy sheet having both a small temperature coefficient of resistance and good press formability, a method for producing the same, and a resistance material for resistors.

The object of the present invention has been achieved by the following.
1) 5.0 to 20.0 mass% of Mn, 0 to 5.0 mass% of Ni, 0 to 5.0 mass% of Sn, and 0.1 to 10.0 mass% of Ni and Sn in total. A copper alloy sheet material containing, the balance being Cu and unavoidable impurities, and having a difference in elongation between the rolling parallel direction and the rolling vertical direction perpendicular to the rolling parallel direction, which is the sheet width direction, being 10% or less.
2) 5.0 to 20.0 mass% of Mn, 0 to 5.0 mass% of Ni, 0 to 5.0 mass% of Sn, and 0.1 to 10.0 mass% of Ni and Sn in total. Containing the balance of Cu and inevitable impurities, the azimuth density of Φ=20 to 35° of τ-fiber obtained from the EBSD measurement result is 4 or more, and the azimuth density of Φ=40 to 80° is less than 4. A copper alloy plate material.
3) In the above 1 or 2, containing 0.01 to 0.5 mass% of Fe, 0.01 to 0.5 mass% of Si, and 0.01 to 0.5 mass% of Fe and Si in total. The described copper alloy sheet material.
4) The copper alloy according to any one of 1 to 3, which has a tensile strength of 400 MPa or more, an elongation of 20% or more, and a volume resistivity of 20 to 70 μΩcm in both the rolling parallel direction and the rolling vertical direction. Plate material.
5) The method for producing a copper alloy sheet according to any one of 1) to 4) above, which comprises casting [step 1], homogenizing heat treatment for holding at less than 900°C [step 2], and hot rolling [step]. 3], chamfering [step 4], cold rolling 1 [step 5], trimming [step 6], annealing 1 [step 7], surface polishing [step 8], cold rolling 2 [step 9], 10°C Annealing 2 [step 10], straightening [step 11]: heating at 400/850° C. or more and holding at 400 to 850° C. for 1 second to 5 hours, and then cooling to normal temperature at a cooling rate of 20° C./min or more. And a method of manufacturing a copper alloy sheet having the respective steps of annealing 3 [step 12] in this order.
6) A resistor material for a resistor, which uses the copper alloy sheet according to any one of 1) to 5) above.

According to the present invention, it is possible to provide a copper alloy sheet having both a small temperature coefficient of resistance and press formability having a good fracture surface shape, a method for producing the same, and a resistor material for resistors.

It is a conceptual diagram of favorable sag. It is a conceptual diagram of bad sagging.

Hereinafter, the present invention will be described in detail.
<Copper alloy plate material>
In the present invention, Mn is 5.0 to 20.0 mass%, Ni is 0 to 5.0 mass%, Sn is 0 to 5.0 mass%, and Ni and Sn are 0.1 to 10.0 in total. A copper alloy sheet material containing 10% by mass or less, the balance of which is Cu and unavoidable impurities, and the difference in elongation between the rolling parallel direction and the rolling width direction, which is perpendicular to the rolling parallel direction, is 10% or less. 5.0 to 20.0 mass% of Mn, 0 to 5.0 mass% of Ni, 0 to 5.0 mass% of Sn, and 0.1 to 10.0 mass% of Ni and Sn in total. , The balance is Cu and unavoidable impurities, and the azimuth density of Φ=20 to 35° of τ-fiber obtained from the EBSD measurement result is 4 or more, and the azimuth density of Φ=40 to 80° is less than 4 It is an alloy plate material.

<<Ingredient composition>>
In order to reduce the temperature coefficient of resistance, the copper alloy sheet of the present invention contains Mn in an amount of 5.0 to 20.0 mass% from the viewpoint of the effect of the interaction between the Kondo effect and lattice vibration. Further, by setting Ni to 0 to 5.0 mass%, Sn to 0 to 5.0 mass%, and Ni and Sn to a total of 0.1 to 10.0 mass%, the temperature coefficient of resistance can be more effective. Can be controlled.

Preferably, Mn is 5.5 to 19.0 mass %, Ni and Sn are 0.01 to 5.0 mass %, more preferably Mn is 6.0 to 18.0 mass %, and Ni and Sn are It is 1.0 to 5.0 mass% in total. Since it is another copper alloy, it contains specific unavoidable impurities.

≪Optional additive ingredients≫
The copper alloy sheet of the present invention contains 0.01 to 0.5 mass% of Fe, 0.01 to 0.5 mass% of Si, and 0.01 to 0.5 mass% of Fe and Si in total. Is preferred. By containing Fe and Si, the tensile strength can be improved, but excessive addition raises the resistance, so the content is preferably 0.01 to 0.5 mass %.

In the composition of the alloy of the present invention, "mass%" may be simply referred to as "%". Among the component compositions of the alloy, the elemental component whose lower limit of the content range is described as "0%" means that it is a component that is arbitrarily added to the copper alloy sheet material as needed, and the elemental component is In the case of “0%”, it means that the elemental component is not contained in the copper alloy plate material or is less than the detection limit value. In addition, "-" includes the numerical range of both ends.

The unavoidable impurities in the present invention mean trace elements that are unintentionally mixed in from the raw material or the furnace wall of the casting furnace during melting and casting. The total amount of unavoidable impurities is generally 50 mass ppm or less, typically 30 mass ppm or less, and more typically 10 mass ppm or less.

<<Difference in growth>>
INDUSTRIAL APPLICABILITY The copper alloy sheet material of the present invention improves the fracture surface shape during pressing by reducing the anisotropy of elongation in the rolling parallel direction (hereinafter also referred to as RD direction) and the rolling vertical direction (hereinafter also referred to as TD direction). The difference in elongation between the RD direction and the TD direction is 10% or less. Here, the difference in elongation refers to the absolute value of the difference in elongation between the RD direction and the TD direction.

By setting the difference between the elongations in the RD direction and the TD direction to 10% or less, during the shearing process of the press punching process before assembling into the resistor, the deformation amount until the fracture is different between the rolling parallel direction and the rolling vertical direction. Since the directionality can be reduced, the sagging ratio of the fracture surface of the press can be reduced. It is more preferably 8% or less, still more preferably 5% or less.

≪Tensile strength and elongation≫
In the copper alloy sheet material of the present invention, the tensile strength is 400 MPa or more and the elongation is 20% or more in both the RD direction and the TD direction in order to suppress deformation and microcracks when incorporated as a resistor.

The tensile strength in both the RD direction and the TD direction is preferably 410 MPa or more and 800 MPa or less, more preferably 420 MPa or more and 750 MPa or less. The elongation is preferably 22% or more and less than 50%, more preferably 25% or more and less than 50%. When the elongation is less than 50%, the elongation up to fracture during press punching can be reduced, and the sag during press punching can be controlled to be small in both the parallel rolling direction and the vertical rolling direction.

≪Volume resistivity≫
When the copper alloy sheet material of the present invention is used as a resistor, it is the resistivity required to detect the voltage drop in the connected electronic circuit, and is preferably 25 to 70 μΩcm.

≪τ-fiber (tau-fiber)≫
Since the difference in elongation between the RD direction and the TD direction of the copper alloy sheet of the present invention is 10% or less, in the present invention, τ-fiber (φ1=90°, φ2=45°, Φ=0 to 0 by EBSD measurement 90°) is controlled such that the azimuth density of Φ=20 to 35° is 4 or more and the azimuth density of Φ=40 to 80° is less than 4.

Here, the τ fiber means {0 0 1}<-1 -1 0> (φ1=90°, φ2=45°, Φ=0°) to {1 1 0}<0 0 1>(φ1= 90°, φ2=45°, Φ=90°) is a general term for azimuths that rotate, and the azimuth density of Φ=20 to 35° is 4 or more is {4 4 11}<11 11 -8> set. The development of the structure, that Φ=40 to 80° is 4 or more means that the rolling texture {1 1 0}<0 0 1> remains. That is, the sag plane is improved by increasing the former azimuth density and simultaneously reducing the latter azimuth.

In addition, τ-fiber uses OIM5.0 (trade name) manufactured by TSL Solutions Co., Ltd. as a measuring device for the EBSD method, and the data of the measuring device is used as OIM Analysis7.31 (EBSD data analysis software) attached to the device. ) Is used for calculation.

By controlling τ-fiber within the above range, the deformation resistance value when plastically deforming a copper alloy sheet changes, and as compared with the case where τ-fiber control is not performed, the fracture in the rolling parallel direction and the vertical direction It is possible to reduce the elongation up to, and as a result, press punching can be performed with less stress, and the sagging in the fracture surface shape can be reduced.
τ-faiber can be controlled by the following manufacturing method.

<Method of manufacturing copper alloy sheet>
The manufacturing method of the copper alloy plate material of the present invention,
Casting [Step 1],
Homogenization heat treatment of holding at less than 900° C. for 10 minutes to 10 hours [step 2],
Hot rolling [step 3],
Chamfering [Process 4],
Cold rolling 1 [step 5],
Trimming [step 6],
Annealing 1 [Step 7],
Surface polishing [Step 8],
Cold rolling 2 [step 9],
Annealing 2 [step 10] of heating at a temperature rising rate of 10°C/min or more, holding at 400 to 850°C for 1 second to 5 hours, and then cooling to room temperature at a cooling rate of 20°C/min or more,
Straightening [process 11],
And annealing 3 [step 12] in this order.

Each step itself is a known step or a combination of improved steps thereof. Particularly, the homogenization heat treatment step of step 2, the annealing and cooling of step 10 are important steps for controlling τ-fiber of the present invention. is there.

In the homogenization heat treatment [step 2], the grain size is suppressed from being coarsened by holding the temperature below 900° C. for 10 minutes to 10 hours, and the subsequent texture formation is facilitated. When heat-treated at 900° C. or higher, it is difficult to obtain the intended τ fiber.

In the annealing 2 [step 10], by heating at a temperature rising rate of 10° C./min or more, holding at 400 to 850° C. for 1 second to 5 hours, and then cooling to room temperature at a cooling rate of 20° C./min or more, τ Controls the orientation integration of the fiber. In particular, when the temperature rising rate is slow and the holding time is out of the above range, a predetermined orientation density cannot be obtained, and elongation anisotropy and sag anisotropy occur.

In the present invention, treatments such as shape correction, oxide film removal, degreasing, and rust prevention may be performed between adjacent steps or after the final recrystallization annealing step. INDUSTRIAL APPLICABILITY The copper alloy sheet material of the present invention is extremely useful as a resistance material for resistors, for example, shunt resistors.

The present embodiment shows an example of the present invention, and the present invention is not limited to this embodiment. In addition, various changes or improvements can be added to the present embodiment, and a mode in which such changes or improvements are added can be included in the present invention.

(Example 1)
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
A ingot having a predetermined alloy composition (mass%) shown in Table 1 is produced by casting [step 1], and homogenized heat treatment by holding for 10 minutes to 10 hours at less than 900° C. before hot rolling [step 2]. Hot-rolling with a total working rate of 50% or more in order to break the cast structure and obtain a uniform structure [Step 3], and chamfering by cutting the surface layers on both sides by 0.5 mm or more to remove oxide scale. [Step 4], cold rolling 1 for rolling at a total working rate of 60% or more to obtain a target shape [Step 5], and removing both ends of the plate material with a dimension of less than 5% of the total width to adjust the shape of the material end. Trimming [step 6], annealing 1 for removing strain of the material at 300 to 600° C. for 10 seconds to 1 hour 1 [step 7], surface polishing for removing an oxide film on the material surface [step 8], Cold rolling 2 to obtain a target shape and for work hardening at a total working rate of 10 to 80% [Step 9], release of strain and temperature rise of 10°C/min or more to obtain Tau-fiber Annealing 2 [step 10], which is heating at a speed, holding at 400 to 850° C. for 1 second to 5 hours, and cooling to room temperature at a cooling rate of 20° C./min or more, rolling to correct warpage and bending of plate material, Alignment in which a stress of 100 MPa or more is applied in the parallel direction [Step 11], and annealing 3 [Step 12] in which heat treatment is performed at a holding temperature of 200 to 500° C. for 5 seconds to 1 hour to remove residual stress of the material is performed. The steps were performed in order to obtain a plate material having a thickness of 0.2 mm.

The alloy composition is as shown in Table 1, but the balance other than the alloy components shown in Table 1 is copper and inevitable impurities. Further, the respective conditions of step 2 and step 10 are as shown in Table 2. The samples thus obtained were evaluated as follows. The measurement was performed on the manufactured sample, which was sampled from 5 points at 1 m intervals in the rolling direction, and the average value thereof was used. The results are shown in Table 3. Unless otherwise specified, the test was performed in an atmosphere of 23° C. and 50% RH.

(Measurement and analysis of crystal orientation by EBSD measurement)
According to the EBSD method, the measurement area was 64×104 μm 2 (800 μm×800 μm) and the scan step was 0.1 μm. The scan step was performed in 0.1 μm steps in order to measure fine crystal grains. In the analysis, the direction distribution function ODF (Orientation Determination Function) was confirmed by the analysis from the EBSD measurement result of 64×104 μm 2. The electron beam was generated by a field emission electron gun. The probe system at the time of measurement is 0.015 μm.

As the measuring device for the EBSD method, OIM5.0 (trade name) manufactured by TSL Solutions Co., Ltd. was used. The plate material was cut into a size of 30×30 mm, mechanically polished to 1/2 the plate thickness, and then electrolytically polished to remove distortion and mirror-finish.

(Measurement of temperature coefficient of resistance and volume resistivity)
The plate surface of the plate material is mirror-polished, and each of the plate material before and after mirror-polishing is subjected to a method (four-terminal method) according to the method specified in JIS C2525 and JIS C2526, and the temperature coefficient of resistance in the range of 20°C to 50°C ( TCR) was measured.

When the absolute value of the temperature coefficient of resistance TCR at 20° C. to 50° C. was 50 ppm/K or less and the volume resistivity ρ at 20° C. was 20 to 70 μΩcm, the pass level was ◯, and when it was out of this range, it was x. The plate thickness of the plate material was measured with a micrometer.

(Cross-sectional shape after press punching)
The shape of the plate material after press punching is determined by the ratio of the sag measured according to the shear test method for copper and copper alloy thin strips specified in the Japan Copper and Brass Association technical standard JCBA T310:2002 to determine the press formability of the plate material. evaluated.

That is, the plate material was punched out using a pressing machine, a square die or the like to expose the cross section (press fracture surface) orthogonal to the rolling direction of the plate material, and the cross section was observed using a scanning electron microscope. The conditions for punching the plate material were preliminarily tried and good conditions were set: a clearance of 10 μm, a pressing speed of 200 mm/s, and a lubricating condition of no lubrication.

In FIG. 1, 1 is sagging during punching, 2 is a shear surface, and 3 is a fracture surface. Here, when the sagging dimension in the sheet thickness direction of 1 is less than 20% of the entire sheet thickness, it was determined that the sagging was small and the dimension was obtained as designed.

(Tensile strength, elongation)
Data obtained by performing a tensile test according to JIS Z 2241:2011 on each sample material (n=3) cut out in a direction parallel to the rolling direction of the plate material (RD direction) with a predetermined test piece size. Calculated from The average values of the calculated tensile strength and elongation are shown. In this example, 400 MPa or higher was set as the pass level.

As is clear from the above, the copper alloy sheet produced by the process of the present invention has a small temperature coefficient of resistance and also has good press formability.

1 Sagging 2 Shear surface 3 Fracture surface 4 Burr

Claims (6)

5.0 to 20.0 mass% of Mn, 0 to 5.0 mass% of Ni, 0 to 5.0 mass% of Sn, and 0.1 to 10.0 mass% of Ni and Sn in total. The balance is Cu and unavoidable impurities, and the difference between the elongation in the rolling parallel direction and the elongation in the sheet width direction perpendicular to the rolling direction is 10% or less. 5.0 to 20.0 mass% of Mn, 0 to 5.0 mass% of Ni, 0 to 5.0 mass% of Sn, and 0.1 to 10.0 mass% of Ni and Sn in total. , The balance is Cu and unavoidable impurities, and the azimuth density of Φ=20 to 35° of τ-fiber obtained from the EBSD measurement result is 4 or more, and the azimuth density of Φ=40 to 80° is less than 4 Alloy plate material. The Fe content is 0.01 to 0.5% by mass, the Si content is 0.01 to 0.5% by mass, and the total Fe content and the Si content are 0.01 to 0.5% by mass. Copper alloy plate material. The copper according to any one of claims 1 to 3, which has a tensile strength of 400 MPa or more, an elongation of 20% or more, and a volume resistivity of 20 to 70 µΩcm in both the rolling parallel direction and the rolling vertical direction. Alloy plate material. It is a manufacturing method of the copper alloy plate material as described in any one of Claims 1-4, Comprising: Casting [process 1], homogenization heat processing [process 2] hold|maintained below 900 degreeC, hot rolling [process 3]. , Surface cutting [step 4], cold rolling 1 [step 5], trimming [step 6], annealing 1 [step 7], surface polishing [step 8], cold rolling 2 [step 9], 10°C/min Annealing 2 [step 10], straightening [step 11], in which heating is performed at the above temperature rising rate, holding at 400 to 850° C. for 1 second to 5 hours, and then cooling to normal temperature at a cooling rate of 20° C./min or more, and A method of manufacturing a copper alloy sheet material, which comprises annealing 3 [step 12] in this order. A resistance material for a resistor, which uses the copper alloy sheet according to any one of claims 1 to 5.

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